Patent GB-1497556-A (GB)
Title: Portable data entry apparatus
IPC: G06F3/023
Filed: 1975-08-06
Abstract: 1497556 Portable data entry apparatus TELXON CORP 6 Aug 1975 [29 Nov (3)] 32886/75 Heading G4A A battery-powered portable data entry apparatus, which may be used to supply data to a telephone link, comprises a keyboard, a microcomputer 100 for generating data entry signals responsive to depression of the keys of the keyboard, recording means including a recording medium for storing the data entry signals, operator-actuable means including the keyboard for searching the recording medium to determine the presence or absence of a selected data entry signal, and operatoractuable means for restoring the recording medium, after the search is completed, to the location at which the recording of data was interrupted to perform the search. The telephone link may be connected to a central computer utilized, e.g. by a supermarket chain. The recording medium may be a magnetic tape, and in a RECORD mode data may be viewed as it is entered on a display 109. If the apparatus is not in the RECORD mode and a data entry is attempted, an audible alarm 112 is activated. An end of data mark character is automatically written on the tape following the final data entry. During the RECORD mode, the three previous data entries to the current data entry are stored in a random-access memory of the microcomputer 100 and may be recalled and viewed by depressing a SCAN key, Fig. 1A (not shown), 1, 2, or 3 times, without moving the tape. During a READ mode, the tape is first rewound. Data entries may then be viewed item-by-item by successively depressing the SCAN key. Alternatively, a search for a selected data entry may be carried out by first depressing any data key and then entering a mask designating the selected data entry. The tape is then moved forward until the selected data entry is found, when it may be viewed on the display 109. If the SCAN key is then depressed again, the apparatus searches for the next occurrrence of the selected data entry, and so on for further depressions of the SCAN key. The READ mode may also be entered from the RECORD mode in such a way that the tenth data entry back is displayed at the initiation of the READ mode. Following a search, the end of data mark character is detected and the tape moved forward to this position in readiness for a subsequent RECORD mode. During a send mode, the tape is read via read/write circuitry 107 and the data entries are transmitted to the telephone link via a modem 122. Battery power is conserved by means of a switching circuit 116 which supplies power to various components of the apparatus only when needed. To further conserve battery power, a powered component is energized only during "awake" times of the switching circuit 116, and is de-energized during "asleep" times, these times in the described embodiment being respectively 2À5 and 7À5 milliseconds. If the battery voltage falls below a first predetermined level, an alarm message is sent to the display 109, and if the battery voltage falls below a second predetermined level, the battery is automatically disconnected. Detailed circuit diagrams of the components of Fig. 2 are given, Figs. 3-23 (not shown), lists of the electrical component values used also being given.